Cyclonic air cleaner

ABSTRACT

An air cleaner device for filtering intake air including a housing defining a chamber, a filter element disposed within the chamber, and a duct element having a passageway in fluid communication with the chamber. Further, the duct element extends along and downwardly from about a portion of the housing and further includes an inlet for drawing intake air into the chamber. The air cleaner having a base member in fluid communication with the chamber and an outlet, where the air drawn into the chamber is filtered by first and second filtering operations to obtain filtered air, with the first and the second filtering operations accomplished at least in part due to a cyclonic motion of the air and passage of the air through the filter element, respectively; and where the filtered air from the chamber of the housing is released through the outlet in the base member.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit under 35 U.S.C. §119(e) of U.S.Provisional Application No. 61/061,502, filed Jun. 13, 2008, theteachings and disclosures of which are incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to internal combustion engines and, moreparticularly, to air cleaner devices and components employed in internalcombustion engines.

BACKGROUND OF THE INVENTION

Small internal combustion engines are used in a wide variety ofapplications including, for example, lawn mowers, lawn tractors, snowblowers, and power machinery. Frequently, such internal combustionengines employ a device to remove contaminants from the combustion airto prevent premature wear of any internal components. Typically, thecontaminants, which mainly comprise air born dirt, sand, cement dust,and chaff from vegetation, are removed from the combustion (or intake)air with a filtering device called an air cleaner. The air cleaner isgenerally attached upstream of the carburetor or throttle valve on sparkignited engines and upstream of the intake manifold on diesel enginesfor preventing abrasive particles from entering the engine's cylinders.

To effectively trap contaminants and other abrasive particulate matter,most air cleaners employ a filtering media that performs a filteringoperation. Generally, the filtering operation encompasses a sievingprocess that traps the contaminant particles as they pass through thefiltering media. With time, the filtering element, which typically has afinite capacity to trap dirt, becomes restricted as trapped particlesbuild up on and within that filter. Furthermore, as the build up on thefilter continues to increase, the air flow continuously becomes more andmore restricted until the point when the engine's performance startsbeing affected. In addition to the continuous build up of debris on thefilter, at least some severe conditions can cause the filter to reachits capacity in a short period of time, thereby requiring frequentreplacement. Replacing the filter element can be both time consuming andcostly for the equipment owner. Thus, it is often desired to employdevices and mechanisms that can provide effective filtering whileextending the life of filter elements.

One such device is a pre-cleaning device, which is often employed inconjunction with an air cleaner device to separate out heavier dirtparticles from the intake air before that air is provided to the aircleaner. By virtue of utilizing such pre-cleaning devices, the volume ofdirt to be removed by the air cleaner filter is reduced. However,utilizing both pre-cleaner and air cleaner devices can significantlyincrease the footprint of the engine. In addition, they can be expensivedevices involving a large number of components that can requireconsiderable maintenance and frequent replacement. Also, many suchconventional pre-cleaning and air cleaner devices are not well-suitedfor allowing efficient engine operation under varying temperatureconditions. For example, pre-cleaning and air cleaner devices utilizedin engines that are designed for operation under warm (e.g., summer)conditions often are incompatible with optimal operation of the enginesunder cold (e.g., winter) conditions.

It would therefore be advantageous if an air cleaner device that caneffectively trap contaminant particles is developed. It would further beadvantageous if such an air cleaner has a smaller footprint and does notrequire frequent replacing of the filter element. It would additionallybe advantageous if such an air cleaner is cost effective to own andmaintain. Also, it would be advantageous if, in at least someembodiments, the air cleaner device was compatible with engine usageunder various temperatures, such as ambient temperatures, and/or otheroperational conditions.

SUMMARY OF THE INVENTION

In at least some embodiments, the present invention relates to an aircleaner having a housing defining a chamber therewithin, a filterelement disposed within the chamber of the housing, and a duct elementhaving a passageway in fluid communication with the chamber of thehousing. Further, the duct element extends along and downwardly fromabout a portion of the housing and further includes an inlet for drawingintake air into the chamber. The air cleaner additionally includes abase member in fluid communication with the chamber of the housing andhaving an outlet, such that wherein the air drawn into the chamber ofthe housing is filtered by first and second filtering operations toobtain filtered air, with the first and the second filtering operationsaccomplished at least in part due to a cyclonic motion of the air andpassage of the air through the filter element, respectively; and wherethe filtered air from the chamber of the housing is released through theoutlet in the base member.

In at least some other embodiments, the present invention relates to amethod of filtering particulate matter from intake air of an engine.

In at least some other embodiments, the present invention relates to anengine comprising an air cleaner capable of being positioned in at leastone of a cool air location in which the inlet is oriented at leastsubstantially away from the muffler and a warm air location in which theinlet is oriented at least substantially towards the muffler.

Other aspects and embodiments are contemplated and considered within thescope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention are disclosed with reference to theaccompanying drawings and these embodiments are provided forillustrative purposes only. The invention is not limited in itsapplication to the details of construction or the arrangement of thecomponents illustrated in the drawings. Rather, the invention is capableof other embodiments and/or of being practiced or carried out in variousother ways. The drawings illustrate a best mode presently contemplatedfor carrying out the invention. Like reference numerals are used toindicate like components. In the drawings:

FIG. 1 is a front view of an exemplary air cleaner device employed in aninternal combustion engine, in accordance with at least some embodimentsof the present invention;

FIG. 2 is a front perspective view of the air cleaner device of FIG. 1,in accordance with at least some embodiments of the present invention;

FIG. 3 is a back view of the air cleaner device of FIG. 1, in accordancewith at least some embodiments of the present invention;

FIG. 4 is a top view of the air cleaner device of FIG. 1, in accordancewith at least some embodiments of the present invention;

FIG. 5 is a cross-sectional view of the air cleaner device as viewedalong lines 5-5 of FIG. 1 rotated 90 degrees counter clockwise, inaccordance with at least some embodiments of the present invention;

FIG. 6 is a bottom view of the air cleaner device of FIG. 1, inaccordance with at least some embodiments of the present invention;

FIG. 7 is a left side view of the air cleaner device of FIG. 1, inaccordance with at least some embodiments of the present invention;

FIG. 8 is a right side view of the air cleaner device of FIG. 1, inaccordance with at least some embodiments of the present invention;

FIG. 9 is a first front perspective exploded view showing the variouscomponents of the air cleaner device of FIG. 1, in accordance with atleast some embodiments of the present invention;

FIG. 10 is a second exploded view showing the various components of FIG.9 rotated counter clockwise 90 degrees, in accordance with at least someembodiments of the present invention;

FIG. 11 is a schematic cross-sectional view of the air cleaner device asviewed along lines 6-6 of FIG. 1 rotated 180 degrees, showing certaincomponents of the air cleaner device and importantly illustrating airflow therethrough, in accordance with at least some embodiments of thepresent invention;

FIG. 12 shows the position of the air cleaner device within the enginein a summer configuration, in accordance with at least some embodimentsof the present invention; and

FIG. 13 shows the position of the air cleaner device within the enginein a winter configuration, in accordance with at least some otherembodiments of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIGS. 1-10, various views of an air cleaner device 2 areshown, in accordance with at least some embodiments of the presentinvention. In particular, FIG. 1 shows a front view of the variouscomponents of the air cleaner device 2, while FIGS. 2 and 3 show frontperspective and back views, respectively, thereof. Relatedly, FIGS. 4and 5 show respective top and cross-sectional views of the air cleanerdevice 2. Additionally, FIGS. 6-8 show respective bottom, left side andright side views of the air cleaner device 2, while FIGS. 9 and 10 showexploded views of the air cleaner device 2, in accordance with at leastsome embodiments of the present invention.

The air cleaner device 2 is contemplated for use in, as part of, inconjunction or combination with, a wide variety of engines 4 (See. FIGS.12 and 13). For example, some embodiments of the present invention canbe employed in conjunction with SORE engines including Class 1 and Class2 small off-road engines such as those implemented in various machineryand vehicles, including, for example, lawn movers, air compressors, andthe like. Indeed, in at least some such embodiments, the presentinvention is intended to be applicable to “non-road engines” as definedin 40 C.F.R. §90.3, which states in pertinent part as follows: “Non-roadengine means . . . any internal combustion engine: (i) in or on a pieceof equipment that is self-propelled or serves a dual purpose by bothpropelling itself and performing another function (such as gardentractors, off-highway mobile cranes, and bulldozers); or (ii) in or on apiece of equipment that is intended to be propelled while performing itsfunction (such as lawnmowers and string trimmers); or (iii) that, byitself or in or on a piece of equipment, is portable or transportable,meaning designed to be and capable of being carried or moved from onelocation to another. Indicia of transportability include, but are notlimited to, wheels, skids, carrying handles, dolly, trailer, orplatform.”

Referring generally to FIGS. 1-10 and particularly to FIGS. 2 and 5, theair cleaner device 2 includes a housing 6 releasably secured to a base8. In at least some embodiments, and as shown, the housing 6 includes ahousing main portion 10 having an inner wall portion 10A that iscylindrical (or substantially cylindrical) in shape and an outer wallportion 10B that is frusto-conical (or substantially frusto-conical) inshape. The inner wall portion 10A and the outer wall portion 10B areconnected, at least in part, by way of a flange portion 10C (describedin greater detail below). Notwithstanding the fact that in the presentembodiment, the main portion 10 of the housing 6 includes innercylindrical and outer frusto-conical wall portions 10A and 10B,respectively, in alternate embodiments, other shapes of those portionsare contemplated and considered within the scope of the presentinvention. For example, both portions can either be frusto-conical orcylindrical in shape.

In addition to the main portion 10, the housing 6 includes a coverhousing portion 12 overlying the housing. The cover housing portion 12can either be releasably connected to the main portion 10 of the housing6 or be integrally formed therewith. In the embodiments in which thecover housing portion 12 is releasably connected to the main portion 10of the housing 6, any of a wide variety of mechanisms including, forexample, various types of screws, nuts, bolts and other fastening and/orengaging mechanisms and/or snap/friction fit can be employed. The coverhousing portion 12 is typically, although not necessarily, shaped andsized to conform to the shape and size of the main portion 10 of thehousing 6. For example, in at least some embodiments in which the mainportion 10 of the housing 6 has a frusto-conical (or cylindrical)profile, the cover housing portion 12 can be circular in shape having adiameter conforming to the diameter of the outer wall portion 10A (orthe inner wall portion 10B) of the housing. In other embodiments, othershapes and corresponding appropriate sizes for the housing 6 and thecover housing portion 12 are contemplated and considered within thescope of the invention.

Still referring generally to FIGS. 1-10 and particularly to FIG. 5,disposed axially within a central or substantially central portion of aninterior chamber 14 of the main portion 10 of the housing 6 is a filterelement 16 for filtering air entering the air cleaner device 2.Typically, any of a wide variety of filter elements 16 that are commonlyavailable and frequently employed can be used for filtering, dependingparticularly upon the level of cleaning required (e.g., granularity ofthe material to be removed). For example, in at least some embodiments,a paper filter element (e.g., a pleated paper filter element) and, moreparticularly, a dry paper filter element sized appropriately forair-flow patterns of a specific application can be employed. In at leastsome other embodiments, filters such as, oil-wetted filters, cottongauze filters and oil bath filters can be employed. In at least somealternate embodiments, other types of filters can be used as well.Additionally, in some embodiments, the filter element 16 can be shapedto conform to the shape of the housing 6 and sized to fit within theinterior chamber 14 of the housing. In at least some other embodiments,the filter element 16 can vary in shape as well.

Referring particularly to FIG. 5, as indicated above, the filter element16 is disposed concentrically and axially within the interior chamber 14with a certain gap or space G between the filter element and the outerwall 10B (it should be noted that the gap G does not generally extendthrough the entire width of the air cleaner device 2, as additionallyshown in FIG. 11) of the housing 6 such that air entering the aircleaner device 2 is circulated around and about the filter element 16 ina cyclonic fashion to remove particulate matter therefrom. Additionally,the filter element 16 is designed to define a filter chamber 18 (e.g., atubular structure or any other hollow structure) surrounded orsubstantially surrounded by a filtering media 20. By virtue of thefilter chamber 18 and the filtering media 20, the filter element 16serves as a sieve in which particulate matter from the air is removed asthat air passes through the filtering media and into the filter chamber.The clean (or filtered) air from the filter chamber 18 then flowsdownwardly, exiting the air cleaner device 2 from the base 8. To ensurea leak-proof (or at least substantially leak-proof) conveyance of theclean air from the filter chamber 18 of the filter element 16 to thebase 8, the filter element is releasably attached to the base, asdescribed in greater detail below. Additional components such as sealsand gaskets can be provided in between the filter and the base.

As indicated above, in addition to the filter element 16, the interiorchamber 14 of the housing 6 has disposed therein the flange member 10C,which extends tangentially from the inner wall portion 10A to the outerwall portion 10B and further extends into the gap G to partially coveran opening 22 in the main housing portion 10. By virtue of thepositioning the flange member 10C within the gap G, the flange memberenables the incoming intake air to be deflected into a cyclonic (e.g.,spiral-like) movement around the filter element 16. In otherembodiments, other such mechanisms can be used to facilitate cyclonicmotion of the incoming intake air. Further, the opening 22 provides anentryway for intake air flowing from an inlet duct 24 to the interiorchamber 14.

Still referring generally to FIGS. 1-10 and particularly to FIGS. 1 and5, the inlet duct 24 defines a passageway that extends along and/oradjacent (e.g., tangentially) an exterior circumferential surface of theouter wall portion 10B, and further extends downwardly (e.g., at a 90degree or substantially 90 degree curve) towards the base 8 of the aircleaner device 2 and terminates in an inlet (or inlet opening) 26.Advantageously, the orientation of the inlet duct 24 prevents fluids,such as rain or spray from a pressure washer from entering directly intothe air cleaner housing 6 through the inlet 26. In addition, to preventlarger debris material or rodents from entering into the air cleanerdevice 2, the inlet 26 has attached thereto a protective screen 28. Theprotective screen 28 can take the form of any of a variety of grills,webs, lattices or grids. Other configurations of the protective screen28 are contemplated and considered within the scope of the presentinvention.

Now referring particularly to FIGS. 9 and 10, the base 8 includes a topportion 30 having a base plate 32 and a bottom portion 34 having anoutlet (or outlet opening) 35 for releasing clean (or filtered) air fromthe housing 6 into the engine 4. The base plate 32 is generally designedto conform to the shape and size of the housing 6 and includes a pair offasteners 36 for ensuring a secure and tight fitting connection betweenthe base 8 and the housing. In some embodiments, more than two, orpotentially even a single fastener, such as a clasp or clasp-likemechanism(s), for connecting the housing 6 to the base 8 can be providedas well. Conventional gasket or sealing mechanisms can be provided inbetween the housing 6 and the base 8 to provide an air tight and secureseal therebetween.

In addition to the fasteners 36, the base plate 32 has formed in acentral or substantially central portion thereof a slot or opening 38(see FIG. 11), through which extends a tubular connector element 40 forconnecting the filter element 16 to the base 8. In particular, a topportion (or edge) 42 of the connector element 40 is connected to thefilter element 16, while a bottom portion 44 of the connector element isconnected via a passage 46 (again, described further with respect toFIG. 11) to the outlet 35. Thus, filtered air from the filter chamber 18of the filter element 16 flows downwardly from the housing 6 towards thebase 8, where that filtered air is transferred through the connectorelement 40, via the slot 38 and out of the outlet 35.

In addition to the aforementioned components, the base 8 can include acollection area 48 for collecting the dust and debris removed from theintake air via the cyclonic action. The collection area 48 furtherincludes a hole or slot 49 (See FIG. 5), where the hole is visiblethrough the gap G for allowing the built up dirt to exit from the aircleaner device 2. Further, the collection area 48 can be integrallyformed with the base 8 (e.g., the base plate 32) or alternatively, canbe separately connected to the base. Although not described, it shouldbe understood that various conventional components like gaskets, seals,supports and other connecting structures and platforms that can beemployed as part of, in conjunction or combination with the base 8 arecontemplated and considered within the scope of the present invention.Also provided on the base 8 is an appendage or tab 50 having a hole 51for connecting the air cleaner device 2 to an external structure by anyof a variety of nuts, bolts and/or screws passing through the hole 51.

Further, the housing 6 including the main housing portion 10 and thecover housing portion 12 and the base 8 can be constructed out of avariety of materials. For example, in some embodiments, each of thehousing main portion 10, the base 8 and the cover housing portion 12 canbe made out of an injection molded plastic. In other embodiments,aluminum castings, stamped sheet metal and/or other engineered plasticor metal elements can be employed. In alternate embodiments, other typesof light-weight and/or corrosion resistant materials can be employed aswell. Additionally and notwithstanding the illustrated profiles of eachof the housing 6 (the main housing portion 10 and the cover housingportion 12) and the base 8 in the present embodiment, it is neverthelessintended that in other embodiments, various other shapes andconfigurations can be employed for each of the housing and the base.Additionally, the inlet duct 24 can be constructed out of one or more ofthe aforementioned materials as well.

Referring again to FIG. 11, in operation and in accordance with at leastsome embodiments of the present invention, intake air laden with dustand other particulate and abrasive matter enters the housing 6 via theinlet 26 of the inlet duct 24 and through the opening 22 (as shown byarrow 52). Particularly, the intake air enters upwardly and axially,with at least a portion of that air entering circumferentially throughthe inlet 26 and travels through the inlet duct 24 to enter the housing6 (e.g., via the opening 22) in a radial direction. Within the housing6, the dust laden intake air is deflected tangentially at a highvelocity, thereby imparting on the air a rotary, cyclonic orcircumferential-type motion. Generally speaking, deflection of theintake air within the housing 6 is achieved by way of the flange member10C, which in at least some embodiments can extend downwardly andperpendicularly from the cover housing portion 12. In addition to therotary motion in a tangential direction, the intake air also moves in aradial direction through the filter element 16 and further, axiallydownwardly towards the base 8 for separation of particulate matter. Inat least some embodiments, the dust laden intake air can move upwardlytowards the cover housing portion 12 in a cyclonic motion and thenaxially downwardly, aided in part by gravity, to be imparted with avortex-type motion for separation of particulate matter from the intakeair. Thus, once inside the interior chamber 14, the intake aircirculates axially as well as circularly (as shown by arrows 54) in acyclonic fashion about the filter element 16 to separate dirt from theintake air. Indeed, the air cleaner employs a centrifugal action forseparating dust from the intake air, particularly insofar as radialacceleration or centrifugal force is used to separate the dirt particlesfrom the air. Thus, the air cleaner device 2 of the present invention isa centrifugal-type device employing a vortex or cyclonic separator forproviding clean (or filtered) air to the engine 4.

By virtue of the high velocity and the circular (or cyclonic) motion ofthe intake air within the interior chamber 14, the heavier dustparticles separated from the intake air are moved outwardly towards theouter wall 10B of the main portion 10 of the housing 6. Those separateddust particles then move downwardly (as shown by arrow 56) from theouter wall 10B, aided by gravity, to collect into the collection area 48of the base 8. The collected dust is then removed through the hole 49(see FIG. 5) of the collection area 48. In general, the internalcombustion engine 4 generates a positive pressure pulse when an intakevalve thereof closes. This positive pressure helps push the built updirt out through the hole 49 of the collection area 48.

Further, the remaining intake air (intake air with the heavier dustparticles removed due to the cyclonic action) is then filtered throughthe filtering media 20 of the filter element 16 such that any remainingfiner dust particles are sieved through and clean (or filtered) air ispassed into the filter chamber 18 (as shown by arrows 58). The clean airthen exits through the center of the filter chamber 18 via the opening38, into the passage 46 and out through the outlet 35 in the base 8(again, as shown by the arrows 58). The clean intake air exiting the aircleaner device 2 is then provided to the engine 4.

Thus, intake (or combustion) air is drawn into the air cleaner device 2through the opening 22 via the inlet 26 of the inlet duct 24 anddeflected by way of the flange 10C within the interior chamber 14 aroundthe filter element 16 in a cyclonic motion. As described above, thecyclonic motion or the air causes a first filtering operation to removeheavy contaminant particles, while passage of the air through thefiltering media 20 into the filter chamber 18 of the filter element 16constitutes a second filtering operation removing any finer particles,thereby resulting in removal of contaminants from the intake air. Thefiltered clean air flows through the filter chamber 18 of the filterelement 16 towards the base 8 and exits out of the outlet opening 35into the engine 4.

In contrast to conventional air cleaners that require pre-cleaner (orpre-cleaning) devices, the present invention provides an air cleanerdevice which eliminates the need for a separate pre-cleaner device,particularly insofar as the air cleaner device 2 provides mechanisms forboth pre-cleaning and cleaning the intake air. To the extent that theair cleaner device 2 encompasses both pre-cleaning and cleaning, the aircleaner device extends the life of the filter element 16 as compared totraditional air cleaners, while improving the quality of filtering.Additionally, by virtue of incorporating the features of bothpre-cleaner and air cleaner devices, the air cleaner device 2 of thepresent invention provides a reduced package size such that thefootprint or the envelope of the space required to attach the aircleaner to the engine 4 is substantially reduced. In addition, the aircleaner device 2 provides considerable cost savings to the equipmentowner. Thus, the air cleaner device 2 presents significant advantagesover conventional air cleaner devices providing a space saving, compact,economical and effective air cleaner device. Embodiments of the presentinvention can be particularly beneficial insofar as the air cleanerdevice 2 incorporates features of both a pre-cleaning device and an aircleaner device.

In addition to the foregoing, the air cleaner device 2 is optimallydesigned to effectively and consistently operate at both high and lowtemperatures. Particularly, the position of the inlet duct 24 about theengine 4 can be altered depending upon the outside temperatures, or moreparticularly, depending upon the summer and the winter conditions. Thesummer and the winter positions of the air cleaner device 2 are shownand explained in greater detail with regard to FIGS. 12 and 13.

Referring now to FIGS. 12 and 13, summer and winter positions (orconfigurations), respectively, of the air cleaner device 2 are shown inaccordance with at least some embodiments of the present invention.Referring particularly to FIG. 12, the summer configuration shows theengine 4 having a muffler 60, a fuel tank 62 and an air cleaner device64 in operational association with one another. Although variousstructures and components including, for example, carburetors,crankcases, intake manifolds and other related parts of a typicalinternal combustion engine are not illustrated, the configuration,relative operation and arrangement of such components is readilyavailable and well known in the art. Therefore, for simplicity andconciseness of expression, a detailed illustration of the engine 4 andany related components is not provided. Nevertheless, such componentsare contemplated and considered within the scope of the presentinvention.

Further, as shown, the air cleaner device 64 is designed to allowpositioning an inlet duct 66 thereof towards a cool air location forroom temperature to high temperature operating environments. Suchpositioning is similarly applicable for moderate to high ambienttemperature operating environments. By virtue of positioning the inletduct 66 towards the cool air position within the engine 4, the cleanedair entering the engine does not over-heat the carburetor and theengine. Advantageously, the summer position of the air cleaner device 64can be changed to the winter position, shown in FIG. 13, by merelychanging the position of the inlet duct 66.

Specifically, in the winter position shown in FIG. 13, the inlet duct 66can be positioned near the muffler 60 to allow heated air to enter theengine 4 during conditions where carburetor icing is a possibility, forexample, due to an operating environment having a low ambienttemperature. The winter configuration (also known herein as ananti-icing configuration) utilizes heat from the muffler 60 to preventsubsequent ice-build up in the carburetor and the intake manifold duringcold weather operation. Thus, the present air cleaner device 64advantageously provides optimal operation during both the summer and thewinter months.

While FIGS. 1-13 as described above show an exemplary embodiment of acyclonic-type air cleaner device having winter and summerconfigurations, the present invention is intended to encompass a varietyof alternative embodiments having one or more features differing fromthose described above. For example, in at least some alternateembodiments, the shapes, sizes, orientations and material ofconstruction of the various components employed in the air cleanerdevice can vary from those shown in FIGS. 1-13. Relatedly, variouscomponents associated with a conventional air cleaner device, such asgaskets, seals, hoses and other related structures, are not shown in thefigures. Such aforementioned components and the manner of operationthereof are readily available and known to people of skill in the art.The absence of a detailed illustration of such components of the aircleaner device 2 herein is also merely for clarification purposes andconciseness of expression. Use of such components is, however,contemplated and considered within the scope of the present invention.

Also, it is contemplated that embodiments of the present invention areapplicable to engines that have less than one liter in displacement, orengines that both have less than one liter in displacement and fitwithin the guidelines specified by the above-mentioned regulations. Instill further embodiments, the present invention is intended toencompass other small engines, large spark ignition (LSI) engines,Electronic Fuel Injection (EFI) engines, Compression Ignition (CI)engines, and/or other larger (mid-size or even large) engines. Inadditional embodiments, the present invention is intended to be usedwith other single or multi-cylinder engines as well.

Further, despite any method(s) being outlined in a step-by-stepsequence, the completion of acts or steps in a particular chronologicalorder is not mandatory. Further, modification, rearrangement,combination, reordering, or the like, of acts or steps is contemplatedand considered within the scope of the description and claims.

It is specifically intended that the present invention not be limited tothe embodiments and illustrations contained herein, but include modifiedforms of those embodiments including portions of the embodiments andcombinations of elements of different embodiments as come within thescope of the following claims.

We claim:
 1. An air cleaner for removing particulate matter from intakeair of an engine, the air cleaner comprising: a housing having a topportion, a bottom portion and defining a chamber therewithin; a filterelement disposed within the chamber of the housing; a duct elementhaving a passageway in fluid communication with the chamber of thehousing, the duct element extending along and downwardly from about thetop portion of the housing, the duct element further comprising an inletfor drawing intake air into the chamber; a base member for releasablysecuring the bottom portion of the housing thereto, the base membercomprising a first portion in fluid communication with the chamber ofthe housing, and a second portion having an outlet and in fluidcommunication with the first portion; wherein the intake air is drawninto the chamber of the housing through the inlet of the duct elementand the duct element passageway and a cyclonic motion is imparted to theintake air; wherein a first filtering operation is facilitated at leastin part due to the cyclonic motion of the intake air and a secondfiltering operation is facilitated by flowing at least a second portionof the intake air through the filter element, the first and the secondfiltering operations for separating particulate matter from the intakeair to obtain filtered air; and wherein the filtered air from thechamber of the housing is conveyed via the first and the second portionsof the base member to be released via the outlet.
 2. The air cleaner ofclaim 1, further comprising a cover member that is one of releasablyattached and integrally formed with the top portion of the housing. 3.The air cleaner of claim 1, wherein the housing has a cylindrical orsubstantially cylindrical profile.
 4. The air cleaner of claim 1,wherein the filter element is a dry paper filter element.
 5. The aircleaner of claim 1, wherein the duct element further comprises aprotective screen releasably secured to the inlet.
 6. The air cleaner ofclaim 1, wherein the first filtering operation results in removal ofheavier particulate matter from the intake air.
 7. The air cleaner ofclaim 6, wherein due to the cyclonic motion of the intake air, at leastsome of the heavier particulate matter moves outwardly and downwardlywithin the chamber towards the base for collection, the downward motionof the particulate matter aided at least in part by gravity.
 8. The aircleaner of claim 1, wherein the second filtering operation causesremoval of finer particulate matter from the intake air.
 9. The aircleaner of claim 1, wherein the first portion of the base furthercomprises a collection portion for collecting the separated particulatematter from the intake air and having an opening for removal of thecollected particulate matter.
 10. The air cleaner of claim 1, whereinthe inlet duct is positioned towards a cool air engine location foroperating environments having a moderate to high ambient temperature.11. The air cleaner of claim 10, wherein the cool air location is atleast substantially away from an engine muffler.
 12. The air cleaner ofclaim 1, wherein the inlet duct is positioned towards a warm air enginelocation for operating environments having a low ambient temperature.13. The air cleaner of claim 12, wherein the warm air location is atleast substantially towards an engine muffler.
 14. A method of filteringparticulate matter from intake air of an engine, the method comprising:providing an air cleaner, the air cleaner comprising: (i) a housinghaving a top portion, a bottom portion and defining a chambertherewithin; (ii) a filter element disposed within the chamber of thehousing; (iii) a duct element having a passageway in fluid communicationwith the chamber of the housing, the duct element extending along anddownwardly from about the top portion of the housing, the duct elementfurther comprising an inlet for drawing intake air into the chamber; and(iv) a base member for releasably securing the bottom portion of thehousing thereto, the base member comprising a first portion in fluidcommunication with the chamber of the housing, and a second portionhaving an outlet and in fluid communication with the first portion;drawing the intake air into the chamber of the housing through the inletof the duct element and the duct element passageway; imparting acyclonic motion to the intake air within the chamber of the housing;performing first and second filtering operations facilitated at least inpart due to the cyclonic motion of the intake air and flowing the intakeair through the filter element, respectively, the first and the secondfiltering operations for obtaining filtered air; and conveying thefiltered air from the chamber of the housing via the first and thesecond portions of the base member to be released through the outlet.15. The method of claim 14, further comprising providing a cover memberthat is one of releasably attached and integrally formed with the topportion of the housing.
 16. The method of claim 14, further comprisingproviding a protective screen releasably secured to the inlet of theduct element.
 17. The method of claim 14, wherein the first filteringoperation results in removal of heavier particulate matter from theintake air such that at least some of the heavier particulate mattermoves outwardly and downwardly within the chamber towards the base forcollection, the downward motion of the particulate matter aided at leastin part by gravity.
 18. The method of claim 14, further comprisingpositioning the inlet of the duct element to correspond to at least oneof a first position and a second position.
 19. The method of claim 18,wherein the first position involves positioning the inlet towards a coolair engine location for room temperature to high temperature operatingenvironments, the cool air location pointing at least substantially awayfrom the engine muffler.
 20. The method of claim 18, wherein the secondposition involves positioning the inlet towards a warm air enginelocation for low temperature operating environments, the warm airlocation pointing at least substantially towards the engine muffler. 21.An internal combustion engine comprising: a muffler; and an air cleaner,the air cleaner comprising: a housing having a top portion, a bottomportion and defining a chamber therewithin; a filter element disposedwithin the chamber of the housing; a duct element having a passageway influid communication with the chamber of the housing, the duct elementextending along and downwardly from about the top portion of thehousing, the duct element further comprising an inlet for drawing intakeair into the chamber; a base member for releasably securing the bottomportion of the housing thereto, the base member comprising a firstportion in fluid communication with the chamber of the housing, and asecond portion having an outlet and in fluid communication with thefirst portion; wherein the air cleaner is capable of being positioned inat least one of cool air location in which the inlet is oriented atleast substantially away from the muffler and a warm air location inwhich the inlet is oriented at least substantially towards the muffler.